Friday, January 16, 2015

Many people have tried to explain this to climate deniers, who chose not to understand it (1). If anyone else is confused by it, this is the bottom line: you need to apply the same standard of proof to a hypothetical change in the warming trend as you would to determining the existence of a trend in the first place.

Having determined that there has been a warming trend of about 0.16C/decade for the 30 years between 1970 and 2000, the correct question is not has the warming stopped OMG (a question you will never be able to answer with a few years of data) but rather is there any reason to think the trend is different from what it was before?

If you determine there's a tiger in your bedroom, and then (wisely) don't go into your bedroom for a while, the test for whether there's still a tiger there in not whether you've heard it roar in the last 5 minutes. Unless you have convincing evidence, you probably should conclude that the tiger's still there, until and unless you get some strong evidence something has changed.

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1.

So, what is wrong with Cruz’s statement? Well, assuming that by
‘recorded warming’, he means the satellite-derived lower atmospheric
surface temperatures his statement is absolutely correct. If he is
referring to globally averaged surface temperatures since 2000, there is
only a very small amount of warming; this small amount of warming is
indeed contrary to the theory of AGW.

Wednesday, January 14, 2015

It means more or less rain, snow, wind, and clouds in various places. It
means different outcomes for plants, whether direct or, since plants
compete for resources, indirect. It means changes for the animals that
eat those plants. And this includes changes for everything that hitches a
ride on those plants and animals, and hence changes for all sorts of
pathogens. Nature, agriculture, forestry, and health will all be
different in the future. The seas will rise as water expands and glacial
ice melts, affecting coastlines and everyone and everything that
resides there. Water supplies will be affected by changing rainfall
patterns, but water demand will also be altered by changing
temperatures. Energy demands will change, too; there may be less need to
heat houses in winter and perhaps greater need to cool them in summer.
Traffic, transport, building, recreation, and tourism, too, will all
feel the impact of a changing climate.

Unfortunately, his ability to think rationally about what that means is, well, disappointing:

For some, the mere fact of these impacts is reason enough for
governments, businesses, and individuals to exert themselves to reduce
greenhouse gases to minimize the change. That is strange logic, however.
Change, after all, can be for the better or the worse, and at any rate
it is inevitable; there has never been a lengthy period of climate
stasis.

There are multiple levels of facepalm committed here. None are entirely new (the boring repetitive nature of climate denier is one of the reasons you do not see more debunkings here) but they are startling from the mouth of a once-respected economist.

You have the notion that climate change is no big deal because "climate is always changing." We might equally argue that being shot in the head is no big deal, because the composition of our bodies is always changing. In other words, it's breathtaking stupid know-nothingism trying to pass itself off as judiciousness.

Of course if changes in temperature of the magnitude we see unfolding today were common in human history, Tol might have a hint of a glimmering of a point here. But in fact, as he well knows, the entirety of recorded human history has taken place with the assistance of an 8,000-year period of highly stable climatic conditions -- what one might call a lengthy period of climate stasis.

Just as there is no logical or scientific basis for thinking that
climate change is new, there is no self-evident reason to assume that
the climate of the past is “better” than the climate of the future. With
just as little logic, we might assume that women’s rights, health care,
or education were necessarily better in the past.

Are we here seeing Tol preparing to abandon an unfulfilling career as an economist, and embark on a mid-life career shift to Platonic philosopher? Because it is philosophers who sit in their studies and worry themselves about self-evident truths derived from pure logic alone. Scientists, even of the dismal sort, are expected to look outside into the world from time to time.

What I can't get over about this essay is how much ignorance it express of basic economic principles, principles that Tol, as a trained and extensively published economist, should know in the marrow of his bones.

Do I exaggerate? Well, economic concepts do not get a lot simpler than sunk capital. Sunk capital means that once you've put your money into certain things, you can't get it back. It follows from that, as even a bright eight-year-old could grasp, that rapid changes in the environment pose a risk to sunk capital.

Tol's claim that the future of the climate is just as likely to be good for humans as it is bad would be applicable to the first human beings setting foot on a new world, presuming they knew nothing at all about it to begin with (an analogy I've explored before.)

If you ask the (ludicrously unprepared) space colonists if they would like it a degree warmer or a degree cooler, they have no rational reason to care. It might be better a little warmer or a little cooler, then again, it might be completely uninhabitable either way.

But of course this is not remotely the situation we are in. Besides the fact that we know we can exist in this climate, and we don't know if we can exist, without a horrific die-off, in a world 3C or 4C or 6C degrees warmer, there is the additional problem, which I alluded to above, that we have trillions or dollars in sunk capital investments optimized for this climate, not a radically different one.

There is no rational question as to whether a sea level rise of 5m is "better" for humans, because we know that vast amounts of capital and high-value property would be destroyed. There is no rational question as to whether a +5C world would be better for farms; at best, some new areas may be opened up to agricultural productive, but the existing farms, and the existing communities they support, will suffer horrific (and expensive) harm.

So the "Hey! Rapid radical climate change could just as easily be to something better!" argument makes no sense at all. And the nonsensical nature of the argument is emphasized with odd and completely irrational comparisons to deliberate progressive reforms: "With
just as little logic, we might assume that women’s rights, health care,
or education were necessarily better in the past"

Now the deliberate change of social rules and government policies to achieve a benefit is compared directly with a massive, unintended set of changes to the earth. What?

The climate of the 21st century may well be unprecedented in
the history of human civilization; the number of people living in
countries with free and fair elections is unprecedented, too. So what?
“Unprecedented” is not a synonym for “bad.”

Does Tol perhaps think that he will appeal to the left with a facile comparison of environmental disaster to the progress of human liberty? Because make no mistake, he is raving. Biological arrangements aren't comparable to social structures. In biological arrangements, unprecedented is bad. If the doctor comes out of your mother's surgery to tell you that they found something "unprecedented," do you think you're about to hear something good about her prognosis?

Rapidly acidifying the oceans versus Thomas Paine publishing Common Sense. Expanding ranges of deadly tropical diseases versus the Voting Rights Act. Are they different? Are they the same? Is Tol seriously arguing this?

He goes on, invoking the shibboleth of "cheap energy" ("Cheap energy fueled the industrial revolution, and lack of access to
reliable energy is one factor holding back economic growth in most
developing countries" but without offering any evidence for either assertion.) Fundamentally, though, this essay represents a step away from Tol's lukewarmism and towards simple climate denial. For years he's published studies of the costs of climate change, studies which consistently found much lower costs than those of his peers. But fallacies like the above go beyond that. Now he seems to be plunging into outright blog scientist logic and advance-stage Curryism.